The invention relates generally to devices for metering the rate and direction of fluid flow and is more particularly directed to a technique for electronically processing and analyzing multiphase signals provided by a fluid flow sensing or sampling device.
Numerous devices are known for monitoring and measuring the flow of fluids through conduits of various kinds. Such fluid metering devices typically comprise a mechanical sensor or probe which is introduced into, or otherwise operatively associated with, the fluid to be metered. By means of a transducer, a physical quantity sensed by the sensor or sampled by the probe is converted into one or more raw electrical signals representative of the fluid flow.
Some flow sensing devices, for example, turbine flow meters, include a pair of pickups which generate a two-phase signal comprising a pair of sine waves 90.degree. out of phase with one another. These devices derive fluid flow information from the zero crossings of the sine waves. As there are only four zero crossings per cycle, however, the resolution of these devices is limited.